Jade is a generic name for the green colored stone that is so synonymous with China. However, there are two very distinctly different minerals collectively known as Jade. They are nephrite and jadeite.
NEPHRITE comes from the Greek word for Kidney which is NEFRÓ. In Latin, LAPIS NEPHRITICUS means Kidney Stone.

Nephrite was mined and carved in China as early as the Neolithic Period (3500 - 2000 BCE). It was so highly acclaimed and regarded as a sacred stone that it was known as "the essence of heaven and earth".

The deposits in China became depleted around 14th century due to extensive use and demand. By 1800 BC, jadeite began to be traded to China from Burma.

Nephrite is a crystalline calcium magnesium silicate. In its pure state, it is white but may be green, cream, yellow, brown, gray, black or mottled because of the presence of impurities, chiefly iron compounds. The white nephrite is very rare. In 2008 Olympics white nephrites were embedded in each athlete’s medal.

Nephrite has a hardness of 6 to 6.5 on the Mohs scale. Its transparency is translucent to opaque and it has a dull, resinous, waxy luster. Nephrite has no fluorescence, unlike Jadeite. By comparison, jadeite is more translucent and vitreous.

Jade had been mined and used as ornaments and ritual objects since the Stone Age. It was considered PRICELESS among the Chinese and Mesoamerican civilizations (the Olmecs, Toltecs, Mayans and Mexicas, also known as the Aztecs). A Chinese proverb states "Gold has a price; Jade is priceless".

In ancient China, nephrite jade had been made into ornaments and ritual objects including funerary amulets which were buried with the dead. Pieces of the jade were carefully placed on and around the dead body including every orifice. This was believed to preserve the body from decay and ensure a smooth journey into the afterlife.

Jade was also highly regarded as a stone for immortality and was likened to the "essence of heaven and earth". The Chinese named a major God known as the Jade Emperor.

Nephrite produces a clear crisp resonance when struck. Perhaps this is the reason why Chinese poets often extols its beauty and elegance. Nephrite jade has also been made into chimes and musical instruments.

Nephrite jade in New Zealand is known as pounamu in Maori language. It is revered as a sacred stone. The Maori, just as the Mesoamericans, also made tools, weapons and ornaments from jade due to its durability. Their most sacred amulet, the Hei Tiki which was never parted from the wearer was made from jade that was specially traced for each family. These personal heirlooms would be buried with them at the time of death. They believed that their ancestral spirits lived within the stone.

Pounamu is so revered by the Maoris that it is now protected under the Treaty of Waitangi. This highly esteemed nephrite jade is so precious in the Maori culture that it is given as an inheritance. They believe that this precious stone contains a tremendous magical power called MANA.

Nephrite has been confused with Serpentine, Aventurine and Chrysoprase. Many green gemstones and artificial glass are natural imitations of jade. Due to its dense structure, nephrite is seldom dyed. However, it can be heat treated or bleached to attain a better color.

Green nephrite is usually darker and more somber than jadeite. It can also be found in a translucent white to very light-yellow form which is known in China as mutton fat jade, in an opaque white to very light brown or gray known as chicken bone jade as well as in a variety of green hues and near black colors. Besides the rare white jade, the vivid emerald green color is the most cherished and valuable nephrite.

Depending on the saturation of trace elements/impurities, some jades are named and colored differently. These trace elements can be diopside, grossularitic garnet, magnetite, chromite, graphite, apatite, rutile, pyrite, serpentine polymorphs, prehnite, talc and titanite. Their trace elements will determine the color of nephrites.

Nephrite has been considered a sacred powerful stone by different people, cultures and civilizations. Ancient people, more so the Mesoamericans who buried their high priests and nobility with jade (Jadeite).

Nephrite is esteemed as a magical stone with tremendous powers. It blesses anyone who touches it. It is named after the kidney because ancient people noticed that it could cleanse and cure any ailments and illness coming from the liver, spleen and kidneys.

In Asia today, nephrite jade is still being used as a talisman and amulet for protection against accidents and illnesses, for good health, long life and prosperity.
Finally, notable deposits of nephrite are found in Australia, Brazil, China (Sinkiang), Canada, Russia, Poland, Taiwan, Zimbabwe, and in the United States such as in Alaska and Wyoming. Nephrite is also the official state mineral of Wyoming. Today the leading nephrite jade cutting centers are in China, Hong Kong and Taiwan.